1. Field of the Invention
The present invention relates to a method of forming a high-function material film such as a metal material film having high hardness, which can be applied to a cutter such as an edge of an electric shaver.
2. Description of the Background Art
Studies have been conducted in relation to an electric shaver cutter, regarding a method of forming a hard mixed layer of titanium etc. on a surface of a base material for preparing a shaver edge. For example, Japanese Patent Laying-Open No. 62-382 (1987) discloses a method of vacuum-depositing titanium on a cutting edge of a polymer material with ion implantation of argon ions, thereby forming a hard layer of titanium.
While this publication discloses conditions such as deposition conditions, an ion acceleration voltage, an ion implantation rate etc. for effectively carrying out the vacuum deposition and ion implantation, there is no disclosure regarding a relation between these conditions and the color tone of the cutting edge. Thus, there has not been a sufficient study generally regarding such a relation between conditions for forming a film of high hardness on a cutting edge and the color tone of the cutting edge. However, the appearance and the color of a product are extremely important factors which determine the commercial value of the product for the consumer. Thus, it is important to control the color of such a hard film which is formed on an edge of an electric shaver.